An old idea of Stephen Hawking’s: Unseen “primordial” black holes might be the hidden dark matter.
It fell out of favor for decades. NOW the Penrose trapped vacuum HORIZON in combination with Fermion repelling of Q-FFF THEORY , IT SEEMS THE RIGHT SOLUTION.
https://bigbang-entanglement.blogspot.com/2021/01/the-new-dark-matter-black-hole-big-bang.html
https://vixra.org/author/leo_vuyk